Before I give you my analysis of Tropical Storm Eta in relation to South Florida, please keep our brothers and sisters in Central America in your thoughts. Eta is not expected to depart that area until Friday. By then, 3 feet of rain may have accumulated, unleashing devastating flooding.
You must know that I am not expecting Eta to restrengthen into a hurricane. The same system that should lift it northwards will produce considerable wind shear and drive dry air into Eta from the west. You can see in the intensity models, in which all but one keep it as a tropical storm through the next 7 days.
Also, I should say beforehand that there is a massive amount of uncertainty. This is a low-confidence forecast from the National Hurricane Center and a low-confidence forecast from me.
Models are in general agreement that enough of Eta will survive so as to emerge and partially restrengthen over the warm waters east of Belize this weekend. As an upper level trough or dip in the jet stream crosses the Gulf of Mexico, the storm is lifted northeastward.
Cuba may face a tropical storm on Sunday, and southern Florida may face one on Monday.
But the official track from NHC has shifted from the northern Bahamas to the Gulf of Mexico in less than 24 hours, and there could be more changes. Last night's ensemble model runs from the Euro (ECMWF) and American GFS pivoted the track forecasts back west after Cuba. That's because that while the upper trough stalls and weakens over Florida, high pressure reestablishes itself in the low levels to start driving the storm away from the Sunshine State.
Given the uncertainties in (1) what will be left of Eta after tangling with the Central American topography; (2) how much can it strengthen before the dry air and hostile upper wind environment reach it; and (3) the steering currents, I would expect further changes in the NHC forecast today through Thursday.
As I said on NBC 6 on Tuesday, let's give ourselves a couple of days before we "lose our minds" over a tropical threat to South Florida. Instead, brace for more rain and potential flooding. That part of the forecast is a lot more certain.
Given our saturated condition from the never-ending rainy season, the 8 to 10 inches being forecast by National Weather Service would be enough to trigger a new Flood Watch soon. I would expect that to be issued no later than Thursday.